Deadly: The death toll from the listeria outbreak that's been traced back to Colorado cantaloupes has now climbed to 29.

The death toll from the listeria outbreak that’s been traced back to Colorado cantaloupes has now climbed to 29, making it the deadliest food-bourne illness outbreak ever recorded in the United States.

The Centers for Disease Control and Prevention (CDC) reported the increase in the total number of deaths earlier this week, and noted that the number of people infected has gone up to 139 in 28 states.

On Wednesday night, a CDC official confirmed that this latest food-borne illness outbreak was the deadliest on record, surpassing the one linked to listeria-tainted cheese that killed 28 people in Mexico in 1985.

‘There were 28 deaths (adults as well as infants) and 20 miscarriages and still-borns from Jalisco,’ the official said in an email.

‘No other outbreak in recent times, since we began collecting/recording data in 1973 comes close. Of course the system for collecting and tracking food-bourne disease is much more precise now.’

The outbreak began in August and stemmed from Rocky Ford-brand cantaloupes sold by Jensen Farms near Holly, Colorado.

The cantaloupes were recalled Sept. 14, and no melons under the recall are still on store shelves.

The deadliest food-bourne illness outbreak on record was in 1924-1925, when typhoid in raw oysters from New York City killed around 150 people and made more than 1,500 sick.

The number of dead continues to rise because listeria lingers inside cells and so can take as much as two months to emerge.

Ben Silk, an epidemiologist at CDC, who has been leading the listeria investigation told USA today: ‘It has some refuge from the immune system, so it can linger and proliferate over a long time course.’

‘With listeria, it’s growing within the person until it reaches some threshold and spills over. From there it migrates from the gut to the liver and then the blood and the central nervous system.’